Cornwall III with 45 set amp

[Rick J B]

 

 

Yeah, unless you're wanting to go deaf you should be able to rock the Casaba with 8 watts through most Klipsch speakers.

 

My RF-82 II's will play louder than I need with 2 watts.

 

You would be amazed if you heard some of the demos that I periodically do with CWs and a 1/3 wpc SET!!!  No one believes me when I tell them what the maximum power is!

 

Maynard

 

 

Those need at least 7000 watts, right?

[Chris A]

The assumptions that PWK made when recommending amplifier power for each model of Heritage loudspeaker is listed in the Dope from Hope article

 

I assume that from your description of how loud it was when you played the Cornwalls with an amplifier that starts to create a great deal of harmonic distortion at 0.33 W RMS output, that either:

 

1) you never play your Cornwalls at anything approaching 90 dBA average with dynamic music having at least 10 dBA crest factor, or

 

2) you like listening to soft clipping a lot, and the opaqueness and "warmness" (i.e., harmonic distortion) of that resulting sound. 

 

For me, I'd like to not be tethered to either of those two conditions and the way out is by simply by adding more available RMS power to the amplifier's capability.  It's not difficult to get more and to still not sacrifice anything sonically.

 

Chris

Edited September 27, 2014 by Chris A

[tube fanatic]

The assumptions that PWK made when recommending amplifier power for each model of Heritage loudspeaker is listed in the Dope from Hope article

 

I assume that from your description of how loud it was when you played the Cornwalls with an amplifier that starts to create a great deal of harmonic distortion at 0.33 W RMS output, that either:

 

1) you never play your Cornwalls at anything approaching 95 dBA average with dynamic music having at least 10 dBA crest factor, or

 

2) you like listening to soft clipping a lot, and the opaqueness and "warmness" (i.e., harmonic distortion) of that resulting sound. 

 

For me, I'd like to not be tethered to either of those two conditions and the way out is by simply by adding more available RMS power to the amplifier's capability.  It's not difficult to get more and to still not sacrifice anything sonically.

 

Chris

Chris, I should have specified a bit about more about my statement.  This demo is usually done in a nearfield system with the listening position at 6-7 feet from the speakers and a maximum level of 85db.  Within those parameters, the amp can easily provide the required power with very low distortion (approx. 4% 2nd harmonic at 330 mw out; and if the speakers are driven from the 4 ohm taps, which lets the minimum impedance be the deciding factor for power output, the distortion is even lower across the rest of the band).  Don Keele's estimate (iirc he did the measurements) in the Dope from Hope suggests that only 90mw/speaker is needed for that level in the specified 3k cu.ft. room (I don't want to get into discussion of reverberant fields, and so on).  I've found it to be slightly less.  I use that amp to simply prove the point that higher power is not necessary for an amazingly involved sonic experience.  Obviously, more "horsepower" never hurts, and for those who want to crank things up a bit, 330mw would be totally inadequate.  I've mentioned that my main involvement in recent years has been extreme budget tube amps, and the folks I cater to simply can't or don't want to spend much on amplification, preferring to put the money into the speakers instead.  I think it's pretty neat that an amp costing less than $300, built like a "battleship," and including many atypical features can be used with speakers like CWs, K-horns, etc. and leave absolutely nothing to be desired sonically (especially when in blind, level-matched, comparisons with some very costly commercial tube amps, the budget unit is considered the better sounding one).  Mine is just one of the many philosophies out there and is neither better nor worse than anything else.  After all, if it sounds good, it is good however it's achieved.  Enjoy!

Maynard

[Chris A]

That seems to me to be an odd argument.  Horn-loaded loudspeakers have a couple of basic advantages over direct-radiating types of loudspeakers (i.e., cone direct-radiators and planars/electrostatics):

 

1) very low modulation distortion (AM, FM, IMD, etc.), and

2) very low compression distortion

 

...and that using SET power amplifiers having too low of output power headroom for the stated goal (or constraint) of "economy" seems in fact to be false economy,  since it takes away both advantages of horn-loaded loudspeakers and substitutes back in much higher THD for "sweetness", which of course isn't on the input recording--turning your music reproduction system into something that isn't really music reproduction anymore. 

 

Recommending more power using an inexpensive Class D amplifier instead makes a lot more sense--if low price is the controlling objective--since both the SET amp and the class D will be indistinguishable at very low output power, but the inexpensive class D amplifier will cost much less than even the SET, and produce a much more audibly accurate sound reproduction, free of harmonics that add "sweetness" and opaqueness (i.e., large amounts of IMD) to your sound reproduction.

 

Otherwise, I recommend the prospective buyer to save a few more shekels for a slightly longer time and then buy a tube-type amplifier (push-pull) with sufficient power headroom, then have something worth the money.  It works the same way for loudspeakers: save your money until you can buy something worth owning.

 

YMMV.

 

Chris

Edited September 27, 2014 by Chris A

[tube fanatic]

We're back in the decades old argument about whether musical reproduction has to be "accurate" to be enjoyable, and whether "accurate" reproduction is more satisfying than "inaccurate" reproduction.  As a case in point, take a typical push-pull Scott or Fisher amp from the early sixties.  If the tone controls are set (using a 'scope) for a flat response (providing a presumed "accurate," but amplified, facsimile of the signal) the amp may not sound as good to some as when the tone controls are used to shape the response in some fashion.  Is the latter person doing himself a disservice?  Or, if a solid state amp with say, .0001% THD is compared with a SET having 5% 2nd harmonic distortion (predominant, as you know), and the former is found to be hard sounding and lacking in musical enjoyment, is that person wrong (I'll add also that the Darling SET which is so popular has around 15% 2nd harmonic output, yet it's considered to be simply amazing)?  Lastly, what about some of the horrible modern recordings with as much as 10db of boost at 10 kHz?  I, and others, find many to be unlistenable and prefer attenuating the high frequency response of the amp to make them as enjoyable as possible.  Is that wrong?  Personally, if I can shape the response characteristics to make something awful sound nice, I could care less if it's an accurate rendition of the original.  As far as class-D vs tubes, we're comparing apples and oranges so I don't know how to address that.  And, to cite an example my wife has often used, is a woman who wears a lot of makeup to enhance or improve her appearance being innacurate?  I think not if it makes her or those she is with happier.  So, I don't know where we can go with this discussion (still fun though! ).  Perhaps some of the other tube guys have some thoughts on this which they can share.

Maynard

[Chris A]

I could care less if it's an accurate rendition of the original.

I believe we understand each other...we can agree to disagree.

 

Chris

Edited September 27, 2014 by Chris A

[mike stehr]

Oh bother...the Forum members are being "misinformed".

[finallygotmyheresies]

I had a guy try to convince me that K-horns require 1,000 watts to sound their best.

[Chris A]

But not PWK...

Edited September 27, 2014 by Chris A

[Audible Nectar]

We're back in the decades old argument about whether musical reproduction has to be "accurate" to be enjoyable, and whether "accurate" reproduction is more satisfying than "inaccurate" reproduction.  As a case in point, take a typical push-pull Scott or Fisher amp from the early sixties.  If the tone controls are set (using a 'scope) for a flat response (providing a presumed "accurate," but amplified, facsimile of the signal) the amp may not sound as good to some as when the tone controls are used to shape the response in some fashion.  Is the latter person doing himself a disservice?  Or, if a solid state amp with say, .0001% THD is compared with a SET having 5% 2nd harmonic distortion (predominant, as you know), and the former is found to be hard sounding and lacking in musical enjoyment, is that person wrong (I'll add also that the Darling SET which is so popular has around 15% 2nd harmonic output, yet it's considered to be simply amazing)?  Lastly, what about some of the horrible modern recordings with as much as 10db of boost at 10 kHz?  I, and others, find many to be unlistenable and prefer attenuating the high frequency response of the amp to make them as enjoyable as possible.  Is that wrong?  Personally, if I can shape the response characteristics to make something awful sound nice, I could care less if it's an accurate rendition of the original.  As far as class-D vs tubes, we're comparing apples and oranges so I don't know how to address that.  And, to cite an example my wife has often used, is a woman who wears a lot of makeup to enhance or improve her appearance being innacurate?  I think not if it makes her or those she is with happier.  So, I don't know where we can go with this discussion (still fun though! ).  Perhaps some of the other tube guys have some thoughts on this which they can share.

Maynard

 

I'll play

 

I think Chris A makes a good case as to the limitations of SET......that said, I would never tell someone who likes SET not to own one - just that they be aware of the limitations. And for someone thinking about SET - or any amp you're going to put some $$$$ into, try to hear one first. Real world demo can focus things in a LOT.

 

When it comes to amplification, I'm in the Lay's potato chip camp - betcha can't have just one. Because no matter what you choose, there are going to be tradeoffs when we're talking about hooking them up to a set of audio magnifiers like the big Klipsch. We can hear all of those little nuances and differences between them. And when it come to "amps for Klipsch", there's a lot of great choices in the tube realm.

 

What SET brings to the table is that micropower that is ohhh so "close". A well designed SET just has that intimacy that few others do. Really good with vocal and natural instrument material - small ensemble, chamber music, and so forth. But get into large orchestra, rock, anything "amplified", and SET shows it's limitations. I do find an allure with SET, but I elected to go a different direction while yet keeping what I liked about SET in mind.

 

This was my foray into the Mac MC30 project. I wanted a very "midrange" focused amp, but even that was a long road of rebuilds and tube rolling. If I had done them up the "normal" typical way - with Illinois or orange drop caps, I likely would have sold them by now. I took a huge gamble (and so did another builder) and spent about $700 on coupling caps to try to rid the amp of those last vestiges of hazy chocolate without making the amp sound overdetailed. We finally succeeded - but I dare say that most would have never gone to that effort. And then the tube rolling, which also makes a difference in the end result - the best vintage tubes really made a difference. They really are "midrange kings" for those 60's and 70's recordings in particular.

 

But in the total highest fidelity sense, there are recordings that show the shortcomings of the MC30 as well, which is what led me to the VRDs. These are an accurate pair in every sense, having the linearity and power supply to handle just about everything you throw at them. But they will also show you all the flaws in the recordings, so those 60's and 70's classics come off a bit less alluring.

 

Which then begs the question: Is it wrong that I enjoy the MC30s so much, especially for those recordings that make up so much of my collection? I certainly don't think so - yet I am certainly aware that there is a more "accurate" solution that will beat the MC30s readily when fed the best recordings. I could have also considered a BAT or other larger power tube amp for this purpose as well.

 

All of which to say there is no right or wrong answer for everyone. I would never tell an SET owner that he shouldn't use that - although I think it prudent that he know it's limitations. Same goes for a set of MC30s. Or anything else. While we might all seek the benchmark of "most accurate", that's not always what we will end up choosing - even when making an educated and proper choice. We choose what works and sounds best for our particular use and taste - and there's nothing wrong with that - so long as it is an INFORMED choice.

 

Now if we could have all of our favorite recordings done like Mobile Fidelity Sound Lab or Telarc, we might be having a different discussion, but that's not the real world.

[Chris A]

I'd bet that there are more than a few old-timers here that have spent the cost of a pair of Jubilees on amplifiers and other gear that they don't really use much--that they may still own or that they didn't fully recover their expenses selling them. 

 

Think about it.  Everything that I said above is predicated on the notion that what you'd like to do is to spend the least amount possible to get to the system of your dreams, and to get there as quickly as possible without losing so much in "failed excursions".   I've got a short list of these failed excursions and I don't like thinking about any of them.  Rather I like spending ~16 hours/day currently listening to Jubs.

 

I realize, of course, that some people like the random walk of failure and dissatisfaction--but I never did.  I'm not really a maximizer when it comes to this stuff. YMMV.

 

Chris

Edited September 27, 2014 by Chris A

[Cut-Throat]

I realize, of course, that some people like the random walk of failure and dissatisfaction--but I never did. I'm not really a maximizer when it comes to this stuff. YMMV.

 

I am one of those that like failure and dissatisfaction. I have 3 SET amps, 2A3, 45 and 300B..... The 45 gives me the most dissatisfaction, and that is why I listen to it most of the time. I bi-amp with 600 watt per channel Class 'D' amps, but most of the time I don't turn  the chip amps on, so that I can listen to my 45 amp clip and achieve the most dissatisfaction. What I am trying to achieve is the ultimate misery and may seek out a 10Y amp so that it can clip at even lower volume than my 45 amp. YMMV.

[Ski Bum]

We get it, Chris.

 

I'll chip in.  I must be one of the strange cases, because I like nice clean linear amps.  SS, class a/b, able to drive low impedance loads w/out hiccups.  When it comes to power, too much is just enough.  

 

As for pp tube amps, those of proper power and complexity are invariably kinda costly, even if you DIY.  I've had a few over the years, including a Scott integrated and ST-70.  They were ok, but never really set the hooks in me.  (Still want a pair of VRDs, though.  Freakin beautiful amps, inside and out.  I think I want them as much for their artistic value as physical objects as much as for any tube thing.)

 

And I have an unshakable addiction to SE sound.  I often think to myself that it's as foolish as Chris' characterization, and it really is, but I keep coming back to them, and can't break their spell whenever I use them.  They are somewhat like Chief Niwot's Curse.  They're imaging champs, and so pure and natural sounding.  Or seemingly so.  I don't care if it's distortion sheen, the effect is cool.  Until they invent holodecks, these little toys are the next best thing.  Plus, they're simple, thus relatively cheap, and accessible to budding solder slingers.  I like single ended pentode as triode types.  Kinda like what Justin Weber makes, good stuff.    

Edited September 28, 2014 by Ski Bum

[jcmusic]

On 9/23/2014 at 4:52 PM, Ritchie said:

I can put 6V6 tubes in my sse with a B+ adjustment, this would give me approx. 1.5-2W. 

Hopefully this will give me some loudness indication but will not tell me how the 45 will behave especially in the bass region with the Cornwalls.

With Cornwalls you will probably need a sub/subs...